The complete sequence of the human CD79b(lgβ/B29) gene: identification of a conserved exon/intron organization, immunoglobulin-like regulatory regions, and allelic polymorphism

摘要

We determined the complete genomic sequence of the humanCD79b(Igβ/B29) gene. The CD79b gene product is associated with the membrane immunoglobulin signaling complex which is composed of immunoglobulin (Ig) itself, associated in a noncovalent fashion with CD79b and a second polypeptide chain, CD79a (Igα/mb1). The sequence and exon/intron organization of the human and mouseCD79bgenes are highly similar. The gene organization suggests that some variant forms of CD79b may arise by virtue of alternative splicing of mRNA. In addition, a number of conserved regulatory sequences commonly found inIggenes are present in sequences which flank the humanCD79bgene. Some of these sequences are distinct from those found in theCD79apromoter. These differences may explain why transcription ofCD79b, but notCD79a, is observed in plasma cells. A newTaq1 restriction fragment length polymorphism is described that is not associated with any structural polymorphisms of the expressed CD79b polypeptid